Running Containers Under Systemd: Exploring Podman Quadlet

Containers are typically deployed in Kubernetes clusters. But at a smaller scale, on a single-node server, or for development purposes, Kubernetes will be overkill. What’s the recommended way to run a fully autonomous application with several interacting containers in these cases?

The answer is systemd. It can orchestrate containers as is an already running process manager, and containers are just child processes. It’s a perfect fit for running containerized workloads without human intervention.

The concept of Quadlet has been introduced in Podman v4.4.0. It’s a systemd-generator that writes and maintains systemd services using Podman. It can manage containers lifecycle (start, stop, restart), volumes, pods, deployments etc. via systemd. The name comes from the following: “What do you get if you squash a Kubernetes kubelet? A quadlet”. Both system and user systemd units are supported to deploy applications without root privileges.

In this presentation, we will discuss what are Podman Quadlets and demonstrate how Podman Kubernetes features can be associated with it to deploy a fully autonomous application.